


truth or dare | fontcest / papysans

by bokkusu_ai



Category: Undertale (Video Game)
Genre: Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), First Kiss, First Time, Fluff and Smut, M/M, Scary Feelings, Sibling Incest, Smut, Truth or Dare, Unwelcomed Boner, blowjob, idkwtftotag
Language: English
Status: Completed
Published: 2020-08-25
Updated: 2020-08-25
Packaged: 2021-03-06 19:35:08
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 6,384
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26104288
Author URL: https://archiveofourown.org/users/bokkusu_ai/pseuds/bokkusu_ai
Summary: Alphys invites the bros and Undyne to play truth or dare at her lab. Their feelings for each other are brought to light because of a dare and some interesting things happen.
Relationships: Alphys/Undyne (Undertale), Papyrus & Sans (Undertale), Papyrus/Sans (Undertale)
Kudos: 38





	1. the dare

**Author's Note:**

  * For [TheBracedNeko](https://archiveofourown.org/gifts?recipient=TheBracedNeko).



Sans straightened up a bit when Alphys bumped his shoulder. Oh, right, it was his turn.

"uhh...", He looked in front of him, at his brother, and then to the one sitting next to him, Undyne. "'dyne, t or d?", he went back to his recent position.

"I'm no wimp Sans, I choose dare! Come at me with whatever you got, I won't back down!!", Heh, we'll see about that one Undyne. Sans grinned.

"then i dare ya' to hug big a.", Undyne went from blue to purple real fast.

You should've seen Alphys, though, because she was a mumbling mess and even seemed to start sweating.

"UHHH, c-choose something else!! Alphys clearly ain't up to the task!!", Undyne quickly argued, swinging her hand to point at the yellow dinosaur's current state.

Aw, it was oh so clear that these two had crushes on each other. How cute.

Sans' smile only grew wider, "uh-uh, no takebacks.", The fish furrowed her eyebrows.

Papyrus started to encourage Undyne, explaining that it was just a kind gesture between friends and it seemed to do the trick.

"Whatever you bag of bones! This will be easy!!!", She quickly shut her eyes and grabbed Alphy's by the waist, pulling her in. The smaller one squealed, it seemed her face couldn't get any redder, but it did.

As quickly as Undyne hugged Alphys she let go, tightening her ponytail. "See, punk? Easy!".

If this were an Anime, Alphys probably would've sprung a nose bleed, instead, she mumbled some inaudible words and wiggled her glasses around.

Sans chuckled and put his arms up in defense, "whatever you say, captain'.".

The brash fish tsked, "Whatever, I'll get my revenge!", she folded her arms together. "Papy, truth or dare!?".

"I choose dare!! I'm no wimp either, Undyne!", Papyrus smiled and it was oh so cute.

Sans' demeanor quickly changed, though, as that annoying fish's next words were, "I dare you to kiss Sans... On the lips! Or- Uh, the teeth!! AGAGAH", the smaller skeleton's face flushed blue.

"uh... paps is my bro, 'dyne.", Sans retorted. He couldn't even look at Papyrus at this point. There goes trying to keep his composure.

"Well duh!! It's just a kiss!", Undyne justified. He finally sat up straight.

"just a kiss my ass! i'm sorry but you're gonna' have to pick somethin' else.", The blue fish then laughed her ugly laugh.

"You've been caught in my trap, Sans! You said no take-backs!!", fuck.

"but we're broth-", He started up again but was cut off.

"It's fine, Sans, I don't mind!", double fuck. If his brother was agreeing with it there was no way he would be able to fight it now!

Sans now had the courage to look at his brother's face. It was dusted with orange, but probably not as flustered as his own was. It was just a platonic kiss, it meant nothing. Just some stupid dare that they'd forget about soon enough.

So why was his soul beating so fast? He didn't like Paps that way, nah, he was his brother. This didn't mean anything.

"ok, ok!", he surrendered. "just get it over with."

The fish giggled and Alphys finally stopped mumbling to revert her attention back to the game. What, was this sick incest crap appealing to them?!

Sans watched Paps scoot to him on his knees, stopping when he was in front of him. Sans gulped. Crap, were they really going to do this?

Papyrus leaned in and looked down at his brother's teeth, letting out a shaky breath. Nope. Nope. Nope, this isn't hot. Papyrus isn't hot. Nothing about this is hot- stop thinking about him naked!!

Then his brother turned his head to the side and leaned in more until Sans could feel their teeth touch. It sent a spark down his spine and he shivered. They stayed like that for a moment and Sans could visibly hear his soul start beating even quicker. It was probably glowing too.

Crap, why wasn't he pulling away from Paps?! Why wasn't Paps pulling away from him?!

Against his better judgment, he pushed in even more, maybe trying to tell Papyrus to lean away because for some odd reason he just didn't have the willpower to do it himself. Instead, the younger one just kissed back harder.  
This felt so perfect, so perfect it scared him. At that thought, he felt his magic start to pool in a certain area. No, he didn't like his brother like this! Why was this happening!?

Sans opened his mouth to tell Paps to stop but was shushed down when he felt another tongue meet his own, intertwining. Stars, Papyrus tasted so good. He almost forgot how wrong this was on so many levels.

Sans let out a small moan as he felt himself become hard. When he realized this, he fell back onto his forearms and broke the kiss. Oh dear Asgore, fuck, fuck, fuck!!! Alphy's and Undyne are watching this!!

Papyrus' eyes widened as he realized what he had just done. He was above Sans with a string of spit connecting their mouths, both panting. The taller skeleton covered his mouth interrupting the line.

Sans scooted away as fast as he could, zipping up his jacket and shoving it over his bulge. "sorry- bathroom.", He almost bolted to his destination.

As soon as he closed and locked the door he slid down it hitting the tiled floor. Shoving his head into his knees he mumbled, "what the fuck did i just do?!". His boner throbbed at the memory of Papyrus looking down at him with lust filled eyes.

Oh no, it became clear, dead clear. He liked his brother, he fucking liked his brother!! He didn't even think he could stoop that low!

He tried to think of something else, trying to will his hard-on away. Damn that stupid fish and her stupid dinosaur girlfriend! He wouldn't have been put into this position if it weren't for them.

He ended up deciding to recite the whole wingdings alphabet in his mind because there was no way he was about to start fapping on Alphy's bathroom floor.

Soon enough it started to go away and he sighed. Hopefully, no one noticed. No, who is Sans' kidding? Of course they noticed! They couldn't have not noticed him get a fucking boner from his brother!

Sans rubbed his temple. He could just teleport home, but he doesn't want Papyrus to worry. Fuck, what is Papyrus going to think?! He probably won't even want to talk to him again!

He should just face it like a man. He kept his jacket zipped up just in case and unlocked the door. Wait, he should wash his hands and flush the toilet first so no one gets suspicious.

After flushing the porcelain toilet and washing his hands with something that smelt like lavender, he left the bathroom.  
He counted to ten and breathed out, then he entered the living room area.

Papyrus didn't even look at him when he stepped foot in the room, fuck.

"H-hey, Sans! W-We uh, we are going to wa-watch Mew Mew Kissy Cutie Two! Care to... uh, j-join?", Alphys asked, meekly.

Sans just nodded and plopped down on the side of the couch, farthest away from his brother.

Fuck this is so awkward, he could feel his face heat up. He could literally cut the tension with a knife.

Alphys put in a DVD and started playing some magical cat girl show that Sans paid no mind to whatsoever. Other than the sounds from the TV, everything was deathly quiet.

All that he could think of was how he was going to say sorry to Papyrus once they get home, and how fucked up he was to actually have enjoyed the kiss.


	2. the aftermath

**Summary for the Chapter:**

> time for le smut ~

After an episode or two, Sans didn't really keep track, they ran out of more to watch. Undyne stood up and stretched. "It's getting late Alphys, I think I should head on home, a proper warrior needs her sleep!", Alphys frowned but agreed with her that it was late.

Everyone said goodbye and Undyne was out the door. Sans shifted in his spot. This is going to be one awkward walk home.

Papyrus collected his things, which were various figurines he brought over, and stood by the door awaiting his brother. Sans stood up and shoved his hands in his pockets, noticing how they weren't in their usual place now zipped up.

"Thanks for having us over, Alphys!", Papyrus told the scientist as he tied his scarf up.

"N-No, t-thank you for co-coming o-over..!", she replied politely.

The younger skeleton opened up the door and exited, waiting outside for Sans. Alphys waved and both the skeletons waved back as Sans also exited the lab.

Sans at least hoped that Undyne was waiting for them outside to walk them through Waterfall, but he stood disappointed as she was already out of sight. There goes trying to make this trip less agonizing.

Papyrus started walking ahead and Sans kicked an orange rock he saw and watched it skid as he followed suit. He took a ketchup packet out of his pocket and chewed on it nervously, the ketchup was gone but the taste was still there, calming him a bit.

The whole trip to Snowdin was unbearably quiet. The only sounds that could be heard were their footsteps and the occasional splash of water through Waterfall. Sans fidgeted a lot, staring at his feet. Papyrus didn't seem nervous, though, he just stood up straight and looked on ahead as he led the way. Stars, Papyrus is so cool.

Sans had a mini panic, of course, now it was obvious to him that he liked his brother way more than a brother, but why did he have to find out that way? While Alphys and Undyne sat there watching them?

He remembered the taste of Paps mouth, the feel of his tongue around his, and the look of his brother's face after the heated moment... He quickly stopped his train of thought and slowed his breathing. This wasn't honorable at all!

Sans swallowed thickly as he realized they were already passing Grillby's, the light of the bar hurting his eyes. That gives him an idea. He cleared his nonexistent throat which caught the attention of Papyrus.

"uh... grilbz is still open... if ya' want i can, uhm, see 'bout stayin' there for the night or somethin'...", Sans cringed at how unstable his voice sounded.

His brother didn't even answer back, just shaking his head no and continuing on the path. Sans sighed and shook some snow off his slipper. Maybe he shouldn't have even said anything.

Soon enough they arrived home and Papyrus started up the steps, unlocking the door. He abruptly stopped, though.

"I'm sorry I used that situation to my advantage, brother, but I thought you enjoyed it too... Is that the reason you'd like to stay at Grillby's?", Sans gave a quizzical glance at Paps' back. His voice sounded slightly hurt, but gentle.

"no, i wanted to stay at grillbz 'cause i thought you were uncomfortable with me- wait, used to your advantage? what?", Papyrus then opened the front door.

"It's nothing, Sans, don't worry about it.", he then proceeded to wipe his boots onto the mat and enter their home.

Sans frowned, Papyrus was being confusing as usual. He decided to drop it, though, less discussion on the matter and the quicker his boner incident can hopefully be forgotten.

Papyrus moved away so Sans could walk inside. As he did so he eyed the couch, the green color seemed to start becking him to sit down and drown out his worries with countless bottles of ketchup and some mindless television.

While Papyrus stood foot at the front door putting away his boots, gloves, and hanging up his prized scarf, Sans entered his way into the kitchen to raid the refrigerator for a few full bottles of the tomato paste.

He heard from the living room, "Sans!! You didn't even wipe off your slippers! What if you tread mud or snow into the house? Carpets are hard to clean, you know!".

Shoving some of the bottles into his arms he argued, "it'll be fine, bro, besides, aren't you planning to clean the whole house this weekend?", Sans then shut the fridge door with his foot and shuffled back into the living room.

"That makes no difference!", Paps pouted. He perked up, though, as he saw Sans sit down on the stained couch and turn on their tv, or, what he saw on the tv more correct.

"Brother! Did you put MTTV on solely with the hopes that it would pique my interest and persuade me to sit and watch it with you?!", Sans sunk further into the corner of the couch.

"nah bro, i only put it on 'cause it's literally the only channel we have down here.", yeah, it may have been the only show on, but it was oh so obvious the older skeleton was lying. Normally, he would just put on the static channel and fall asleep in record time.

Paps let out a sound similar to a squeal and ran over to claim his seat, closer than Sans liked to admit.

While he watched the flamboyant robot dance around on the television screen, or whatever he was doing because once again Sans was paying absolutely no mind to anything, he started on his first ketchup bottle and sighed, grinning happily. Everything seemed to be going back to normal! He and Papyrus could just completely ignore what happened at Alphy's lab and go on with their human hunting days, or pretending to human hunt that is.

Yep, ignoring, that's exactly what Sans was doing as he felt Papyrus shift closer to him. And then even closer... he chewed on the tip of the ketchup container's lid nervously. His brother was probably just getting comfortable, that's all. No need to worry.

It was hard not to worry, though, when Papyrus' leg hit his own. A mistake? He didn't pull away. Sans could feel the blush forming on his face, and as he side glanced up to look at his brother's, it was dusted with a bit of orange as well. He started to chew harder.

Sans focused on the tv, and now that he was actually paying mind he realized that the oversized calculator was acting out a scene in a very popular monster movie, how original. Even though he had shifted his attention, it didn't really defeat the fact that his body seemed to be hyper-aware of the position of his and his brother's leg to each other. It seemed like the area they were touching was on fire.

Sans side glanced up at his brother's face again, he seemed to have his full attention on the MTTV show. Maybe he didn't know that their legs had touched? He decided that the best course of action was to move his leg away.

So he did just that, but as his leg strayed away it was stopped by a shiver traveling down his spine. Papyrus had grabbed his thigh bone, halting his movement. Sans froze for a moment, he could feel his face heat up more and his soul beat faster. Crap.

He looked up at Paps for the umpteenth but his brother still was seemingly enraptured with the television, like nothing was happening at all. Sans bit down onto the nib of the ketchup bottle, ruining it.

His mouth felt dry but he tried to speak up, "uh... paps, that's uh-", Papyrus glanced down at him and made eye contact that made Sans look away, "...that's my thigh.".

All Sans got as a response was an, "I know!", which didn't calm him down.

The younger skeleton's hand stayed there for a while, and Sans couldn't deny he liked the feeling, but it didn't help with his anxiety. He had continued biting the tomato paste bottle's lid but had started up the habit of bouncing his other leg trying to calm himself down.

All he could think of was Papyrus' damn face as they pulled away from that kiss. He tried not to though because he started to feel magic pool into a certain area. Popping another boner while his brother was around, no, from his brother, was not ideal.

Sans furrowed his eyebrows, Paps had acted strangely during that kiss, and what he said on their doorstep was weird as well. Did his brother return his feelings?

His mind turned a blank for a second, stopping his thinking, Papyrus just twitched his hand. No, he didn't twitch it, he moved it.

He didn't stop moving it. Sans stared at his brother's hand traversing its way up his thigh. He gulped as he realized its destination and started to see a faint blue glow that was growing brighter by the second show through his pants. Fuck, this wasn't good. So why wasn't he stopping him?

"paps... i-", he couldn't even think straight at this point, let alone speak.

"Hm? What is it?".

"what are you-", he cut himself off with a breathy moan, that he quickly covered up with his free hand, when he felt Papyrus' fingers grasp around his clothed member.

"Is this alright...?", the younger one asked. His grip tightened for a sec that made Sans twitch.

Was this alright? No, it wasn't, this was his brother! Although his dick was telling him otherwise...

"... yeah", he answered, reluctantly, moving his arm so his voice could be heard.

"May I see?", he asked quietly, loosening his grip.

Sans grit his teeth, unable to say no. Forgetting how wrong this was he let his guard down and nodded his skull, starting to get hot and bothered.

Paps turned a bit as he lifted his hand off of Sans to grab the hem of his shorts and started to pull them down. Sans exhaled a breath and closed his eyes, it's not like he was proud of his cock or anything, he just hoped it wasn't so disgusting Papyrus would run for the hills.

He felt his pants pull down further and soon cold air rushed over his bones. It felt good in a way, but now that his dick was on full display he had other thoughts. Clenching his grip on the ketchup bottle he tightened his eyes and waited for a reaction from his brother.

"Wowie...", the older one traced his phalanges around Sans' pelvis bone, earning a shiver. He continued, feeling the curves of his pelvis but not going near his magic.

"papyrus...", he wined. He didn't mean to sound so needy but it was starting to hurt.

The taller skeleton stopped for a moment, almost as if he was thinking.

"I don't mean to be lewd but... Do you think I could taste it?", Sans' eyes widened to meet Papyrus' own. Taste it??

"u-uh yeah, sure... whateva' you want...", did he mean a blowjob? How did his brother even come to know these things?

Sans watched as Paps scooted off the couch. He soon realized the severity of the situation as Papyrus kneeled down in front of him.

"w-woah! um... you really don't h-have to-", Paps is acting so out of character, surely this would be an activity fit to be way unruly for the Great Papyrus, so why was he the one initiating it?

Papyrus grabbed his femurs, opening his legs up, "Do you not want this...?", he asked.

Sans clenched his jaw and just nodded, unable to speak. He could stop him but couldn't bring himself to do it once he saw the orange glow behind Pap's teeth. Oh, stars this was wrong on so many levels.

On that note, Papyrus opened his mouth and his tongue lolled out, making Sans' breathing hitch. He leaned his head in and looked at his brother one last time in case he wanted to back out. Upon no protest, he gave the blue-tinted dick a slow lick from base to tip that made Sans shudder and clamp a hand over his mouth to stop any lewd sounds from escaping.

"Sans...", the smaller skeleton just groaned in response, too embarrassed to answer. He couldn't even look when Papyrus opened his mouth over his member and opted to shut his eyes instead. Letting go of his mouth he grabbed the side of a couch cushion for support as he felt Papyrus take him in.

"ah..! p-paps not so fast!-", he moaned out as Paps started to lean his head in more, a little more than the halfway mark.

"Hmm?", he hummed, causing vibrations.

"d-don't talk with your mouth full- ..heh-", Sans moaned out, his legs opening more involuntarily.

Aware of his gag reflex, Papyrus couldn't make it to the bottom and instead bobbed his skull up and down about halfway, swirling his tongue as he got to the top.

Sans felt himself bite back the muscle of his own he had forgotten he conjured, the feeling almost too good, making his spine start to arch some.

Sans couldn't take it, Papyrus was surprisingly talented, suspiciously so one might say, at the action but it just wasn't enough. Without thinking he placed a shaky hand on the back of his brother's skull pushing him down until he reached the bottom, "f-fuck..- ah yes..!", his moan drew louder when he heard Pap's produce a choked 'nyeh'.

He felt his dick twitch at the sound but let go quickly, "ah shit bro i-i'm so sorry..!".

As soon as a small 'pop' was heard from Papyrus releasing his member he wiped the drool away from his mouth, tears in his eyes from the gag, "I-It's ok brother!", his soul pounding with arousal, seemingly caused by the choking.

He sat there for a moment, thinking. Sans started to get anxious until he finally opened his mouth again, "In fact, I, heh, wanted to try something... else? Of course, if you don't mind..!", Papyrus said shyly, tracing his hand up Sans' femur teasingly that caused another shiver.

"w-what is it..?", Sans asked before giving a nervous chuckle, still slightly panting from the stimulation from the sadly short blowjob.

The taller skeleton looked away out of slight shame as he was still on his knees, "I... uh, I wanted to try intercourse with you..?", he suggested, almost mumbling with his face covered in orange.

Sans sat wide-eyed as he tried to process what his brother had just asked him, "inter.. w-what??", he started to panic.

"I-If you don't feel comfortable with that, uh, I u-understand!", he reassured, "I just, nyeh, uh, have wanted this for a while...", he scratched his cheek from embarrassment.

Sans just looked at him, his boner still throbbing. This was real right? His brother was asking him to have sex with him? That he had feelings for him? He felt slightly guilty that he actually welcomed the idea...

Papyrus, feeling awkward that his brother hadn't spoken up yet, continued, "Uhm... Well, it's just... it's a romantic gesture, and, uh, I thought... maybe, nyeh, u-uhm.. we could...", he rambled, now losing the confidence he had mustered up in the beginning.

Sans interrupted his quiet mumbles, "well, uh, a-are you sure? that you, heh, want this..?", he asked, trying to forget the fact that Paps was still placed in front of his dick.

The orange dusted one perked up, "Y-Yes! Stars yes..! A-After what happened at Dr. Alphy's lab I... heh, I couldn't stop imagining you underneath me... as shameful as that is to say...".

Sans exhaled the breath he hadn't known he was holding, "i.. i wouldn't mind that..", he agreed, still very erect. He released his death grip on the empty ketchup bottle as Paps started sitting up.

"R-Really?!", he asked, excitedly.

He finally let go of the ketchup container, discarding it next to him on the cushion he resided on while Paps made his way off the floor.

As the tall one was now standing up fully Sans noticed his boner and felt his soul flutter at the sight, "y-yeah bro..", he consented again.

Papyrus shifted in his shorts, looking at the couch in an almost revolted way, "Shall we move to my, uh, bedroom...? The couch wouldn't be the most ideal place to.. uh, you know... d-do such things.".

Sans smiled, finding Paps charming, "fuck? no, we can go to your room.", he agreed, pulling up his shorts.

Starting to stand up Sans immediately sat back down, his knees still quite wobbly caused by the stimulation from earlier.

Papyrus noticed this and spoke up, "Would you, would you like me to carry you...?", he asked, starting to bend over to scoop the smaller one up.

"uh, yeah.. sure.", at that the younger skeleton lifted him up, starting to carry him bridal style. Sans grunted some, his boner starting to hurt from lack of attention again.

As they started their journey to the stairs Paps slowed down a bit, leaning his skull in to give his older brother a skele-kiss on his forehead. Sans smiled at the feeling, rubbing the spot affectionately, and as they started traversing up the steps Papyrus elaborated, "I love you Sans... a lot.".

He covered his face with his arm out of embarrassment, "i... i love you too paps..", the feelings mutual.

Soon they reached the top of the stairwell, arriving in front of Papyrus' bedroom. Luckily the door was already opened, and with his hands full he had to push it the rest of the way with his foot.

Entering his brother's bedroom it was quite dark, as the lights were off to save power while they weren't home. Papyrus laid Sans carefully onto his mattress, and once he was out of his grasp he walked over to flip on the overhead light.

Sans laid sprawled against the racecar bed, admiring Paps. Stars, his brother was so cool. His dick throbbed, making him think of other things, and as Papyrus made his way back to the mattress he realized just how skimpy his 'armor' was. He tried to stop his eye lights from raking their way up and down his brother's body, out of respect. (Although I think the term 'respect' has already been thrown out of the water by this point, Sans.)

Paps made his way over to the older one, and when he arrived at his destination he took in the sight before bending over and placing himself between his brother's femurs like before, only this time on top.

With Papyrus leaning over him, he could feel his breath. It tingled his bones. Their pevlis' were extremely close but unwavering as they didn't make their way to touch, it seemed to almost be teasing in fashion.

Staring into each other's eye sockets for a moment, Papyrus broke the silence, "You're beautiful, brother...", he exclaimed quietly, leaning his skull in.

"i could say the same about you, bro.", he couldn't stop the genuine smile plastered on his face as he repeated Pap's actions, leaning in until a small clack was heard. It almost felt like magic was sparked at where their teeth had touched.

Papyrus let out a small sound and started to kiss a bit rougher, feeling the same desperate heat that Sans did.

As his dick throbbed for the umpteenth time Sans couldn't hold back anymore so he grabbed the hem of his brother's battle body to draw him in closer, causing their clothed members to touch through fabric, "hnng-", he groaned.

"Ah..! Sans-!", Papyrus moaned, opening his mouth. The smaller one took this as an opportunity to snake his tongue into his brother's mouth in the same fashion as he had done to him a little while ago.

He relished in the taste for a moment, feeling Pap's muscle dance with his, only to arch his back in a pleased manner as Papyrus gave an even thrust upwards, providing the friction he so desperately desired.

They both produced a needy moan, leaving Papyrus wanting more, "S-Sans, please...", he slightly begged.

Hearing the one on top plead his name made the grip on the other's battle body tighter, finding not only a new favorite taste but sound as well, "go ahead..", his voice sounded husky, unlike his own and it made him cringe.

At that note Paps hastily moved out of the way so that he could pull Sans' basketball shorts down, when they were taken off of him Sans sighed a sound of relief from being freed. Papyrus' movements slowed, though, as he couldn't just haphazardly throw his clothing onto the floor, no, he had to carefully fold it and place it next to them. Sans chuckled, finding it cute. He took off his jacket laying it next to him, a rush of cold air wafting over his humeri, helping him relax.

Next was Pap's own shorts, and as he hesitantly grabbed the hem of them, "U-Uh could you, uhm, look away... just for a moment...", he asked quietly.

His brother nodded and turned his head to the side, draping the same arm that had let go of his brother's 'armor' over his face and closed his eyes. He heard fabric shifting and after a while the mattress started moving slightly as Papyrus inched his way back in between the smaller one's legs, "O-Ok...", he said, catching Sans' attention.

As soon as Sans moved his arm and opened his eyesockets the first thing he saw was that Papyrus' was now bare naked, his battle body, shorts, and bodysuit gone and now folded neatly next to Sans' discarded shorts. He bit back his tongue, unable to refrain looking over Pap's bones. Paps glanced away embarrassingly, although they were just bones he still felt slightly ashamed, after all, how could they ever compare to Sans?

"bro... y-you're so.. perfect..", he reassured, reaching out to brush his hands down Papyrus' ribs. That's when he finally looked down, seeing his brother's dick.

While Paps soaked up the attention to his breastplate Sans let his eyes wander over his member. The orange color was quite charming and at a second glance he realized Papyrus was actually quite bigger than he was. He felt some pre leak out of him at the thought of being entered by him...

Papyrus scooted in even closer, the bottom of Sans' thigh bones resting upon the top of his own. When he leaned in again their dicks touched, and now that they were bare it felt so much better, "Mmn..-".

"hahh- shit..", he produced a moan as Papyrus kissed down his jawline, reaching his neck and giving it a small nip. He moved his head out of the way for easier access, which was awarded by more affectionate skele-kisses.

The heat seemed to be turned up when Papyrus started using his hands to feel up Sans. It started with his arms, rubbing them shortly, then caressing his ribs until one of his hands trailed under his stained shirt and up his spine, under his sternum.

"p-pa- fuck- ..!!", he couldn't help arching his spine again, pleasure radiating from his soul.

He continued that up for some time, his fingers exploring all the dips and curves while Sans gripped the sheets below him. It was quite the image, while arousal dripped through him he had to stop.

Paps move his head and hands away, well not without a whimper from Sans at least, looking down and using his free phalanges to rub the pre across his own shaft, grunting a bit at the friction. Sans enjoyed the sight, but soon was met with his brother's eye lights instead, "Can I...?", he asked shyly.

"fuck yea- w-wait don't you have to like.. stretch me or, uh, somethin' first?", he suggested awkwardly, feeling a mixture of nervousness and overwhelming excitement as this was his first time.

Paps shook his skull 'no', lining himself up and getting his legs into a better position. Leaning back over Sans he placed his arms on either side of his shoulders, looking into his eyesockets, "S-Sorry for being so hasty but I don't think I can hold back much longer...", he said with a coy smile.

Sans shook his head, disagreeing, "no it's fine, i don't think i can wait anymore either...", he looked down at where their bodies were about to connect, feeling a tiny ounce of fear but not backing out.

At that Papyrus slowly started giving some force, trying his best to enter. The process was slow, the task proving to be more difficult since he was so tight but after a few moments just the tip made its way in, leaving Paps gritting his teeth and Sans already throwing his head back.

"Y-You're so, gah- tight..", he grunted, starting to push in more.

Now with no tomato bottle to hold onto he let his death grip claw at the sheets, "ha-..", feeling more pre drizzle it's way down him he realized he wouldn't be able to last long, and they hadn't even started.

Halfway in Papyrus had to stop, panting, he leaned in and started to kiss Sans' neck, unable to not show affection to his brother.

Sans felt himself clench around Pap's, was he in all the way? It sure felt like it. He slowed his breathing, involuntarily producing small moans at the attention to his neck.

Paps stopped kissing but kept his skull in the crook of his neck. When he pushed in for a final time the pleasure felt too much, biting Sans' collarbone he let out a muffled groan, the feeling of an ache being relieved, "Mmmn..!!".

That hadn't been expected, he thought that with the pause of movement meant he was already finished entering him. Sans' back arched fully, pain and pleasure searing through his bones like wildfire, "p-paps..!!!!", he practically yelled, tearing some of the sheets that he was grasping onto with. His tongue fell out of his mouth, unable to think of anything other than being filled by Papyrus, and how fucking good he felt inside of him.

Papyrus started to pull out too soon, Sans having no time to adjust, "b-bro-", though that was drowned out as Paps slammed back into him leaving his bones rattling, "gah!!! ah fuck- stars..!", he yelled again, the pleasure covering up and hiding the pain he felt. More tears fell down his face, hitting the fabric beneath them.

The hold Papyrus had on Sans with his teeth was let go, as he gave another hard thrust, "B.. Broth- Sans..!! Hahh..- Shit..! Mmmn.. y-you feel.. so- Good!!", the lewd word had escaped his throat without a chance to cage it back in, Papyrus tried to cover it up, starting up a pattern of rams that felt deeper and deeper as he went on.

Sans didn't notice the curse word, and if he did it seemed to only fuel his seek for higher pleasure. Twisting his hips some he gave a weak attempt at matching Pap's sheer speed at which his thrusts were going, "p-paps please..! f-faster..-", he cried out with a package of complimentary moans to offer as well.

Papyrus bit his tongue, barely able to stop his mouth from opening, he straightened out his spine and sped up this extremely sloppy workout, getting slightly dizzy as he felt himself get closer and closer to the edge.

Sans wasn't any better off, his vision starting to white out. The only thing that existed at this point was Papyrus and him in this scorching room, heated by the satisfaction and need to be closer than ever before from both parties. He wasn't even keeping track of what he was saying, feeling his cock twitch as he drew nearer to the edge.

"S-Sans I'm gonna- ..!", Paps warned, his hips getting harder to control and his thrusts becoming more random and out of line.

"p-paps, in me..! please cum- inside-!!", he got out, unable to feel any shame now. Sans quickly let go of the bedsheets and opted to grab ahold of Papyrus' ribs as pleasure wracked his body. His legs jolted, hurting from being in an unusual open position for so long, and his eyelids shut tightly, pulling his brother in and kissing him roughly. As soon as he felt their tongues touch he practically screamed into the gesture, his member releasing semen onto both skeletons and the bed.

When the smaller one reached his climax Papyrus could feel his walls clamp around him tighter than ever, a feeling that was pulsing in a way. His dick throbbed and twitched, breaking the kiss he rubbed his mouth down Sans' neck, not capable of staying still. Giving one last hard thrust he grunted loudly, "S-Sans!!! Fuck..!!!!", and came deep inside him.

Sans had gone limp, letting go of Papyrus' ribs and letting his back finally fall flat onto the bed. He whimpered softly at the feeling of cum shooting inside of him, he felt full and weirdly comfortable. Almost peaceful.

The taller one stayed in a moment, admiring the sight underneath him through half-lidded eyes. The room had gone awfully quiet, only the pants of the two skeleton brothers were audible.

Sans suddenly felt empty when Paps exited him, pain crackling through him as well. Oh, his legs sure were going to hurt for some time.

The sight only got better for Paps as he scooted away some, his brother looked like the epitome of the characters from the xxx cartoons he had caught Alphys watching at one point, orange cum dripping down his brother's pelvis bone. He stared pervertedly, not even trying to will his eyes to look in another direction. Papyrus smiled, somewhat proud of his work in an odd way.

He glanced away eventually, though, flipping down next to Sans while he sighed, "T-That was.. That was really good..", he said, voice laced with astonishment.

"damn... heh, damn right.", Sans agreed, trying his hardest to turn his body so that he could drape his arm over the one next to him. Snuggling into him he could hear his soul beat rapidly while it tried to calm down his overexerted body.

"I.. I love you, Sans.", Paps said again, pulling him in closer, rubbing his hand up and down his arm affectionately.

"I love you too, bro.".

**Notes for the Chapter:**

> thanks for reading! this was a request from an old friend, her quotev is: TheBracedNeko ( sadly she was caught, and is no longer allowed online, but she still has some pretty cool stories if you'd like to check out her old works! )

**Author's Note:**

> ~ i have no life ~


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